Machine dishwashing formulations generally contain inorganic phosphate salts as builders to sequester calcium and magnesium ions in water to minimize filming of dishware.
Because of environmental considerations associated with the use of phosphates as builders, formulations have been developed without phosphate and chlorine compounds. Non-phosphate formulations generally contain salts of low molecular weight organic acids, such as sodium citrate, as builders. Since citrate is not as effective a builder as phosphate, other additives, known in the art, such as polymers of acrylic acid are used to minimize the increase in spotting and filming that occurs with non-phosphate formulations.
The use of detergent compositions containing copolymers of the alkylene oxide adducts of allyl alcohol and acrylic acid is described in the art.
GB 2,225,589A, filed Dec. 1, 1989 (assigned to Kao), discloses:
An abrasive liquid cleanser composition comprising:
(a) a higher fatty acid alkanol amide or alkylene oxide adduct; PA1 (b) an alkali metal salt of an alkyl benzene sulfonic acid; PA1 (c) 3 to 70% of a water insoluble abrasive; PA1 (d) 0.1 to 5% by weight of one or more of water soluble polymers with a molecular weight of from 200 to 10,000 such as a polyacrylic acid salt, a polymaleic acid salt, a salt of copolymer of acrylic acid and maleic acid, a salt of copolymer of isobutylene and maleic acid, a salt of copolymer of styrene and maleic acid, a salt of copolymer of allyl alcohol and maleic acid and a salt of copolymer of disobutylene and maleic acid. PA1 (a) from about 92 to about 30 percent by weight of one or more C.sub.3 -C.sub.6 monoethylenically unsaturated carboxylic acids, such as acrylic acid; PA1 (b) from about 5 to about 50 percent by weight of one or more aminoacryloyl derivatives such as dimethylamino propylacrylamide (DMAPA); and PA1 (c) from about 3 to about 25 percent by weight of one or more monoethylenically unsaturated monomers such as acrylamide, methacrylamide and allyl alcohol polymerizable with (a) and (b). PA1 (a) polyoxyethylene or polyoxypropylene condensates of aliphatic carboxylic acids, whether linear or branched-chain and unsaturated or saturated, containing from about 8 to about 18 carbon atoms in the aliphatic chain and incorporating from 5 to about 50 ethylene oxide or propylene oxide units. Suitable carboxylic acids include "coconut" fatty acids (derived from coconut oil) which contain an average of about 12 carbon atoms, "tallow fatty acids (derived from tallow-class fats) which contain an average of about 18 carbon atoms, palmitic acid, myristic acid, stearic acid and lauric acid. PA1 (b) polyoxyalkylene (polyoxyethylene or polyoxypropylene) condensates of aliphatic alcohols, whether linear- or branched- chain and unsaturated or saturated, containing from about 8 to about 24 carbon atoms and incorporating from about 5 to about 50 ethylene oxide or propylene oxide units. Suitable alcohols include the "coconut" fatty alcohol, "tallow" fatty alcohol, lauryl alcohol, myristyl alcohol and oleyl alcohol. INDUSTROL.RTM. DW5 surfactant is a preferred condensate of an aliphatic alcohol type surfactant. INDUSTROL.RTM. DW5 surfactant is available from BASF Corporation, Mt. Olive, N.J. PA1 (c) polyoxyalkylene (polyoxyethylene or polyoxypropylene) condensates of alkyl phenols, whether linear- or branched- chain and unsaturated or saturated, containing from about 6 to about 12 carbon atoms and incorporating from about 5 to about 25 moles of ethylene oxide or propylene oxide. PA1 (d) Particularly preferred nonionic surfactants are selected polyalkylene oxide block copolymers. This class can include polyethoxylated polypropoxylated propylene glycol sold under the tradename "PLURONIC.RTM." made by BASF Corporation, Mt. Olive, N.J., or polypropoxylated-polyethoxylated ethylene glycol sold under the tradename "PLURONIC-R.RTM." made by the BASF Corporation, Mt. Olive, N.J. The first group of compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol (see U.S. Pat. No. 2,674,619). The hydrophobic portion of the molecule which, of course, exhibits water insolubility, has a molecular weight from about 1500 to 1800. The addition of the polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole and the liquid character of the product is retained up to the point where the polyoxyethylene content is about 50 percent of the total weight of the condensation product. The latter series of compounds called "PLURONIC-R.RTM." are formed by condensing propylene oxide with the polyethoxylated ethylene glycol condensate. This series of compounds is characterized by having an average molecular weight of about between 2000 and 9000 consisting of, by weight, from about 10 to 80 percent polyoxyethylene, and a polyoxypropylene portion having a molecular weight between about 1000 and 3100. PA1 (i) peroxybenzoic acid and ring-substituted peroxybenzoic acids, e.g. peroxy-alpha-naphthoic acid, and magnesium monoterphtalate. PA1 (ii) aliphatic and substituted aliphatic monoperoxy acids, e.g. peroxylauric acid, peroxystearic acid and 6-(N-phtyalimido) peroxyhexanoic acid. Typical diperoxy acids useful herein include alkyl diperoxy acids and aryldiperoxy acids, such as: PA1 (iii) 1,12-diperoxydodecanedoic acid PA1 (iv) 1,9-diperoxyazelaic acid PA1 (v) diperoxybrassylic acid; diperoxysebacic acid and diperoxysiophthalic acid PA1 (vi) 2-decyldiperoxybutane-1,4-dioic acid.
U.S. Pat. No. 5,308,532, issued May 3, 1994 (assigned to Rohm and Haas), discloses: water soluble terpolymers, useful in automatic dishwashing detergent formulations, containing:
However, none of these references disclose the use of copolymers of the alkylene oxide adducts of allyl alcohol and acrylic acid in nonionic surfactant containing, non-phosphate automatic dishwashing compositions.
Further, the presently available non-phosphate formulations, while environmentally sound, are not as effective in preventing spotting and filming.
It has now been surprisingly discovered that the addition of certain copolymers of the alkylene oxide adducts of allyl alcohol and acrylic acid dramatically minimizes the spotting and filming of non-phosphate machine dishwashing compositions.